Data relating to earth formations are acquired by logging operations for purposes of oilfield exploration and development. Such operations, including wireline logging, measurement-while-drilling (MWD) and logging-while-drilling (LWD), typically use a downhole tool having various electronic components for collecting, storing, and transmitting data.
After drilling a well, various electronic devices may be fixed to a production tubing for purposes of analyzing hydrocarbons and other fluids present in the borehole or wellbore, and for control of fluid flows in the borehole. In this, various electronic devices typically are used for purposes of production logging.
Seismic data gathering and long term reservoir monitoring are other applications that require deployment of electronics in completed boreholes. Sensor arrays may be deployed in the borehole by various means and sensor data gathered and transmitted uphole by a telemetry system for processing and analysis. Robust and durable tool electronics are necessary for such operations.
Recent developments in drilling technology require that electronics such as the mentioned sensors should be capable of withstanding exposure to significantly higher pressures and temperatures that are encountered at increasing well depths. In this, conventional electronics degrade or fail in performance characteristics when exposed to temperatures approaching 200 degrees Celsius (° C.). Therefore, there is a need for improved electronic tool systems that are capable of operating effectively at temperatures in the range of 200 degrees Celsius and above.